Cancer Lung Cancer Causes & Risk Factors Is COPD a Risk Factor for Lung Cancer? By Lynne Eldridge, MD Lynne Eldridge, MD Facebook Lynne Eldrige, MD, is a lung cancer physician, patient advocate, and award-winning author of "Avoiding Cancer One Day at a Time." Learn about our editorial process Updated on November 09, 2022 Medically reviewed by Sanja Jelic, MD Medically reviewed by Sanja Jelic, MD Sanja Jelic, MD, is board-certified in sleep medicine, critical care medicine, pulmonary disease, and internal medicine. Learn about our Medical Expert Board Print Chronic obstructive respiratory disease (COPD) is considered an independent risk factor for lung cancer in more ways than one. Not only is tobacco smoking the number one risk factor for both diseases, but even never-smokers who develop COPD are more likely to develop lung cancer than those who don't. How COPD can trigger the onset of lung cancer is not entirely clear but, as a group of progressive obstructive diseases—which includes chronic bronchitis and emphysema)—COPD is known to cause profound and irreversible changes to the airways. It is not entirely surprising, therefore, that COPD is most commonly linked to squamous cell carcinoma, the type of cancer that develops in the airways. The Most Common Types of Lung Cancer BSIP / Getty Images How COPD and Lung Cancer Are Connected Dozen of studies have linked COPD to lung cancer. Excluding all other risk factors, COPD appears to double the risk of lung cancer compared to people who do not have COPD. Among smokers with COPD, the risk is increased five-fold. All told, around 1% of people with COPD will develop lung cancer each year, most commonly squamous cell carcinoma. The two diseases are also linked by the timing of their appearance, which almost invariably increases with age. COPD principally affects smokers over 40 and is 2.5 times more likely to occur in people over 60. This dovetails with the onset of lung cancer, which most commonly affects smokers (both current and former) by age 70. According to a 2018 review in the International Journal of Chronic Obstructive Pulmonary Disease, between 40% and 70% of people with lung cancer have co-existing COPD. This includes people who have not been diagnosed with COPD but have evidence of obstruction based on pulmonary function tests. The similarities between the two diseases are perhaps best highlighted in a 2012 review of studies published in the European Respiratory Journal: COPD Lung Cancer Main risk factor Smoking Smoking Ages affected (generally) 50-80 65+ Rank, common causes of death 4th 7th % smokers developing in lifetime 10% to 15% 10% to 15% Increased risk due to >20 pack-year history 450% 300% Effect of quitting (>10 years) 65% reduced severity 50% to 75% reduced risk Pack-Years of Smoking and Lung Cancer Risk Theories Behind the Link There are many theories as to why COPD increases the risk of lung cancer. It is believed that multiple factors contribute, including genetics, environment, and lifestyle. Genetics One theory is that there are genetic abnormalities common to both COPD and lung cancer. The overlapping genetic susceptibility is believed to make some people more likely to develop both diseases. Scientists have identified a number of gene mutations commonly seen in people with COPD and lung cancer. These mainly occur on chromosome 6 and include mutations of the CHRNA3, CHRNA5, FAM13A, HHIP, HTR4, and VEGFR1 genes. Nicotine addiction is also linked to commonly shared genetic mutations. DNA methylation, a process in which the function of a gene is changed even if the genetic structure is intact, is also seen with COPD and lung cancer. DNA methylation is known to promote lung inflammation in people with COPD while inhibiting tumor suppressor genes that regulate cell division and repair damaged cells. DNA methylation is known to affect two genes linked to both COPD and lung cancer: CCDC37 and MAP1B. The Role of Genetics in Lung Cancer Cilia Damage Another theory is that the destruction of cilia in the airways exposes the lungs to higher concentrations of carcinogenic (cancer-causing) substances from cigarettes and environmental pollution. Cilia are tiny hair-like structures in the lining of the airways that brush toxins toward the trachea (windpipe) and mouth to be expelled. Cigarette smoke effectively paralyzes these structures and causes them to flatten out over time. With COPD, the persistent inflammation can cause irreversible widening and stiffening of the airways, known as bronchiectasis. When this occurs, the cilia meant to protect the lungs are all but destroyed. This allows the roughly 70 carcinogens found in cigarette smoke unimpeded access to the smaller airways and air sacs of the lungs. Pulmonary Inflammation Yet another theory is that chronic inflammation triggered by COPD places oxidative stress on airway tissues. Oxidative stress is essentially an imbalance between the production of free radicals that cause harm to DNA and antioxidants meant to neutralize them and keep cells healthy. When oxidative stress is increased, the ability of DNA to synthesize proteins can be severely impaired, leading to the formation of abnormal cells. Oxidative stress caused by COPD can also damage telomeres (the structures at the end of chromosomes that tell cells when to die). If both of these things occur, not only can cancer cells develop, but they will effectively become "immortal," replicating and invading tissues without end. 9 Chronic Diseases Closely Linked to COPD What to Do If You Have COPD If you have COPD, talk to your healthcare provider about the risk of lung cancer. Because the two diseases share common risk factors, there will be things you can do to significantly reduce your risk of cancer while reducing the severity and frequency of COPD symptoms. Quit Smoking No matter how many years you have smoked, it is never too late to stop. A 2018 study from Vanderbilt University Medical Center found that quitting cigarettes for five years decreases the risk of cancer by no less than 39%. Many smoking cessation aids are provided free of charge under the Affordable Care Act, allowing you multiple quit attempts per year without having to pay a cent. Secondhand smoke should also be avoided. Take COPD Treatments as Prescribed COPD medications, when used properly, reduce the severity and frequency of attacks while tempering the underlying inflammation that drives the disease. However, only around 33% of people on COPD medications are fully adherent. Check Your Home for Radon Radon, an odorless, colorless gas emitted from the breakdown of uranium in soil, is the leading cause of lung cancer in people who have never smoked. If you have COPD, the risk of radon exposure is increased. To reduce your risk, buy an inexpensive radon home test at a local hardware store, and contact contractors in your area about radon mitigation if the readings are high. Get Screened If you have COPD and a history of smoking, you may be eligible for annual lung cancer screening. The test, involving a low-dose CT scan of the chest, can reduce the risk of death from lung cancer by as much as 20%. The test is intended for older adults who are heavy smokers. It is less useful in younger adults or those who are not at high risk of lung cancer. Guidelines for Lung Cancer Screening Currently, the U.S. Preventive Services Task Force recommends annual lung cancer screening in people who meet all of the following criteria:Are between the ages of 50 and 80Have a 20-pack history of smoking or greaterContinue to smoke or have quit in the past 15 years 10 Ways to Prevent Lung Cancer A Word From Verywell If you have COPD, it is important to be aware of your increased risk of lung cancer. This is true whether you currently smoke, smoked in the past, or have never smoked a cigarette in your life. Because most lung cancers are diagnosed in the advanced stages when they are less treatable, the most important thing you can do is to remain linked to medical care, ideally a qualified pulmonologist. Even if you aren't eligible for lung cancer screening, the routine monitoring of your lungs and lung function can often provide clues as to the onset of lung cancer. How Lung Cancer Is Diagnosed 18 Sources Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy. Baddini-Martinez J. Not every irreversible airflow obstruction is COPD. J Bras Pneumol. 2016;42(4):304-5. doi:10.1590/S1806-37562016000000196 Durham AL, Adcock IM. The relationship between COPD and lung cancer. Lung Cancer. 2015;90(2):121-7. doi:10.1016/j.lungcan.2015.08.017 Durham AL, Adcock IM. The relationship between COPD and lung cancer. Lung Cancer. 2015;90(2):121–127. doi:10.1016/j.lungcan.2015.08.017 Liu Y, Pleasants RA, Croft JB, et al. Smoking duration, respiratory symptoms, and COPD in adults aged ≥45 years with a smoking history. Int J Chron Obstruct Pulmon Dis. 2015;10:1409-16. doi:10.2147/COPD.S82259 De Groot PM, Wu CC, Carter BW, Munden RF. The epidemiology of lung cancer. Transl Lung Cancer Res. 2018;7(3):220-233. doi:10.21037/tlcr.2018.05.06 Young RP, Hopkins RJ, Christmas T, Black PN, Metcalf P, Gamble GD. COPD prevalence is increased in lung cancer, independent of age, sex and smoking history. Eur Respir J. 2009;34(2):380-6. doi:10.1183/09031936.00144208 Sekine Y, Katsura H, Koh E, Hiroshima K, Fujisawa T. Early detection of COPD is important for lung cancer surveillance. Eur Respir J. 2012;39(5):1230-40. doi:10.1183/09031936.00126011 Wilk JB, Shrine NR, Loehr LR, et al. Genome-wide association studies identify CHRNA5/3 and HTR4 in the development of airflow obstruction. Am J Respir Crit Care Med. 2012;186(7):622-32. doi:10.1164/rccm.201202-0366OC Tessema M, Yingling CM, Picchi MA, et al. Epigenetic repression of CCDC37 and MAP1B links chronic obstructive pulmonary disease to lung cancer. J Thorac Oncol. 2015;10(8):1181-8. doi:10.1097/JTO.0000000000000592 Tilley AE, Walters MS, Shaykhiev R, Crystal RG. Cilia dysfunction in lung disease. Annu Rev Physiol. 2015;77:379–406. doi:10.1146/annurev-physiol-021014-071931 National Cancer Institute. Harms of cigarette smoking and health benefits of quitting. Pastor MD, Nogal A, Molina-Pinelo S, et al. Identification of oxidative stress related proteins as biomarkers for lung cancer and chronic obstructive pulmonary disease in bronchoalveolar lavage. Int J Mol Sci. 2013;14(2):3440-55. doi:10.3390/ijms14023440 Córdoba-Lanús E, Cazorla-Rivero S, Espinoza-Jiménez A, et al. Telomere shortening and accelerated aging in COPD: findings from the BODE cohort. Respir Res. 2017;18(1):59. doi:10.1186/s12931-017-0547-4 Tindle HA, Stevenson Duncan M, Greevy RA, et al. Lifetime smoking history and risk of lung cancer: Results from the Framingham Heart Study. J Natl Cancer Inst. 2018;110(11):1201-7. doi:10.1093/jnci/djy041 Humenberger M, Horner A, Labek A, et al. Adherence to inhaled therapy and its impact on chronic obstructive pulmonary disease (COPD). BMC Pulm Med. 2018;18(1):163. doi:10.1186/s12890-018-0724-3 Yoon J, Lee J, Joo S, Kang D. Indoor radon exposure and lung cancer: A review of ecological studies. Ann Occup Environ Med. 2016;28:15. doi:10.1186/s40557-016-0098-z Wender R, Fontham ET, Barrera E Jr, et al. American Cancer Society lung cancer screening guidelines. CA Cancer J Clin. 2013;63(2):107–117. doi:10.3322/caac.21172 US Preventive Services Task Force. Screening for Lung Cancer: US Preventive Services Task Force Recommendation Statement. JAMA. 2021;325(10):962–970. doi:10.1001/jama.2021.1117 By Lynne Eldridge, MD Lynne Eldrige, MD, is a lung cancer physician, patient advocate, and award-winning author of "Avoiding Cancer One Day at a Time." See Our Editorial Process Meet Our Medical Expert Board Share Feedback Was this page helpful? Thanks for your feedback! What is your feedback? Other Helpful Report an Error Submit By clicking “Accept All Cookies”, you agree to the storing of cookies on your device to enhance site navigation, analyze site usage, and assist in our marketing efforts. Cookies Settings Accept All Cookies